Jerry,
If D6 smoked then the relay K1 would have switched to TX mode.
IF the polarity was reversed then D7 would have smoked.
Most of the transistors are safe from polarity reversal due to the diodes
in series with power / collectors.
Raj
At 09-06-2017, you wrote:
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It appears to be the same part
as the 1n4148w diodes used in the diode ring mixer, in an SOD-123
package:?
However, if you reversed the power supply leads into your Bitx40, you
could have blown just about all of the semiconductors on the board.
You might wind up having to buy a new Bitx40, use this one for spare
parts.
Another issue is giving a few volts over 12v, since Q13 and R141 are
already a bit beyond their maximum dissipation limits.
Adding an LM2940T-12 as per??
/g/BITX20/message/26492
would protect from both reversed supply leads and voltages beyond
12v.? It also limits current to something manageable.
Perhaps something like this should be included in the board layout if it
rolls (or in the uBitx).
Jerry, KE7ER
On Fri, Jun 9, 2017 at 03:55 am, <mattcarus@...> wrote:
- Powered up my BITX40 last night and some smoke escaped from D6 :( - I
assume it'll need replacing which is fine, can anyone tell me what
package size it is?
Raj vu2zap